Import upstream version 1.26

[debian/tar] / m4 / openat.m4

diff --git a/m4/openat.m4 b/m4/openat.m4
index eec426a401b0bc73aff33b8f9fb72c1f5939dc89..28c0e1dafbd713cfe661e83d2ca11a8f2b92228c 100644 (file)
--- a/m4/openat.m4
+++ b/m4/openat.m4
@@ -1,7 +1,7 @@
-# serial 30
+# serial 31
 # See if we need to use our replacement for Solaris' openat et al functions.
 
-dnl Copyright (C) 2004-2010 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -63,6 +63,9 @@ AC_DEFUN([gl_FUNC_OPENAT],
 # gl_FUNC_FCHOWNAT_DEREF_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]])
 AC_DEFUN([gl_FUNC_FCHOWNAT_DEREF_BUG],
 [
+  dnl Persuade glibc's <unistd.h> to declare fchownat().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   AC_CACHE_CHECK([whether fchownat works with AT_SYMLINK_NOFOLLOW],
     gl_cv_func_fchownat_nofollow_works,
     [
@@ -96,6 +99,38 @@ main ()
   AS_IF([test $gl_cv_func_fchownat_nofollow_works = no], [$1], [$2])
 ])
 
+# gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]])
+AC_DEFUN([gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG],
+[
+  dnl Persuade glibc's <unistd.h> to declare fchownat().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CACHE_CHECK([whether fchownat works with an empty file name],
+    [gl_cv_func_fchownat_empty_filename_works],
+    [AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <unistd.h>
+            #include <fcntl.h>
+          ]],
+          [[int fd;
+            int ret;
+            if (mkdir ("conftestdir", 0700) < 0)
+              return 2;
+            fd = open ("conftestdir", O_RDONLY);
+            if (fd < 0)
+              return 3;
+            ret = fchownat (fd, "", -1, -1, 0);
+            close (fd);
+            rmdir ("conftestdir");
+            return ret == 0;
+          ]])],
+       [gl_cv_func_fchownat_empty_filename_works=yes],
+       [gl_cv_func_fchownat_empty_filename_works=no],
+       [gl_cv_func_fchownat_empty_filename_works="guessing no"])
+    ])
+  AS_IF([test "$gl_cv_func_fchownat_empty_filename_works" != yes], [$1], [$2])
+])
+
 # If we have the fchownat function, and it has the bug (in glibc-2.4)
 # that it dereferences symlinks even with AT_SYMLINK_NOFOLLOW, then
 # use the replacement function.
@@ -104,6 +139,7 @@ main ()
 # Also use the replacement function if fchownat is simply not available.
 AC_DEFUN([gl_FUNC_FCHOWNAT],
 [
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_CHOWN])
   AC_CHECK_FUNC([fchownat],
     [gl_FUNC_FCHOWNAT_DEREF_BUG(
@@ -112,6 +148,12 @@ AC_DEFUN([gl_FUNC_FCHOWNAT],
                   [Define to 1 if your platform has fchownat, but it cannot
                    perform lchown tasks.])
        ])
+     gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG(
+       [REPLACE_FCHOWNAT=1
+        AC_DEFINE([FCHOWNAT_EMPTY_FILENAME_BUG], [1],
+                  [Define to 1 if your platform has fchownat, but it does
+                   not reject an empty file name.])
+       ])
      if test $REPLACE_CHOWN = 1; then
        REPLACE_FCHOWNAT=1
      fi],